Liquid flow control valves

ABSTRACT

This invention is concerned with means for controlling the flow of liquid through a drop pipe into a vessel comprising a valve movable between a closed position in which the liquid can flow at a limited rate only and an open position in which the liquid can flow at a higher rate, a releasable locking device normally preventing movement of the valve from the closed to the open position, a pneumatic operating chamber, means responsive to the pressure in the operating chamber for releasing the locking device, a relief passage communicating with the operating chamber and having an opening adjacent the delivery outlet of the drop pipe, thereby maintaining the pressure in the operating chamber substantially normal until the said opening is blocked by the rise of liquid level in the vessel, and means for applying a pressure differing from that of the atmosphere to the operating chamber, whereby upon said opening becoming blocked said nonatmospheric pressure is established in the operating chamber and the locking device is released.

United States Patent [72] Inventor William Frank Judd London, England[21] Appl, No. 748,371 [22] Filed July 29, 1968 [45] Patented July 6,1971 [73] Assignee Whessoe Limited [32] Priority Aug. 21, 1967, Sept. 4,1967 [33] Great Britain [31 l 38428/67 and 40341/67 [54] LIQUID FLOWCONTROL VALVES 7 Claims, 3 Drawing Figs.

[52] U.S.C1. 141/198, 137/386, l37/630.l5, 251/94 [51] 1nt.Cl 867d 5/04[50] Field oISearch 137/386, 630.19; 141/13, 192, 198,206, 209,214, 215,225, 226, 367, 392; 251/24, 38,94, 102, 110, 117

[56] References Cited UNITED STATES PATENTS 2,626,632 l/l953 Hillman141/225 X 2,659,384 ll/l953 Lowe 251/117X 2,710,019 6/1955 Reasoner etal. 137/630. 15 X 3,138.170 6/1964 Schaetzly 3,451,444 6/1969 MurrayPrimary Examiner-Laverne D. Geiger Assistant Examiner- -Edward J EarlsAttorney-Holcombe, Wetherill & Brisebois ABSTRACT: This invention isconcerned with means for controlling the flow of liquid through a droppipe into a vessel comprising a valve movable between a closed positionin which the liquid can flow at a limited rate .only and an openposition in which the liquid can flow at a higher rate, a releasablelocking device normally preventing movement of the valve from the closedto the open position, a pneumatic operating chamber, means responsive tothe pressure in the operating chamber for releasing the locking device,a relief passage communicating with the operating chamber and having anopening adjacent the delivery outlet of the drop pipe, therebymaintaining the pressure in the operating chamber substantially normaluntil the said opening is blocked by the rise of liquid level in thevessel, and means for applying a pressure differing from that of theatmosphere to the operating chamber, whereby upon said opening becomingblocked said nonatmospheric pressure is established in the operatingchamber and the locking device is released.

PATENTED JUL m SHEET 1 BF 3 Hal.

PATENTED JUL 5 IBII SHEET 3 OF 3 FIGB INVENTOR. WILLIAM FRANK JUDDLlQUlD FLOW CONTROL VALVES When discharging highly inflammable liquidsthrough a drop pipe into a tanker, static electricity can be generatedwith consequent risk of explosion or fire. The buildup of electricalcharges is dependent on the velocity of discharge of the liquid from thedrop pipe and on the contents or residue in the tank at the time offill. In order to minimize the risk, it has been recommended that therate of discharge should be limited (to approximately 70 gallons perminute for a 3-inch pipe and approximately 120 gallons per minute for a4-inch pipe) until the end of the drop pipe has been completelysubmerged in the liquid. The present invention provides liquid flowcontrol means adapted to ensure compliance with such a recommendation.

ln accordance with the present invention, means for controlling the flowof liquid through a drop pipe into a tanker or other vessel comprise avalve movable between a closed position in which the liquid can flow ata limited rate only and an open position in which the liquid can flow ata higher rate, a releasable locking device normally preventing movementof the valve from the closed to the open position, a pneumatic operatingchamber, means responsive to the pressure in the operating chamber forreleasing the locking device, a relief passage communicating with theoperating chamber and having an opening adjacent the delivery outlet ofthe drop pipe, thereby maintaining the pressure in the operating chambersubstantially normal until the said opening is blocked by the rise ofliquid level in the vessel, and means for applying a pressure differingfrom that of the atmosphere to the operating chamber, whereby upon saidopening becoming blocked said nonatmospherie pressure is established inthe operating chamber and the locking device is released.

The passage through which the liquid can flow at a limited rate may bepermanently open, the starting and ending'of the delivery flow beingcontrolled by means of any suitable construction disposed on theupstream side of the valve above referred to, and this valve may bemoved automatically to its open position by the pressure of the liquidbeing delivered when the locking device is released to permit suchmovement, biasing means being provided to return the valve to its closedposition when the delivery flow is stopped.

In an alternative arrangement, the passage through which liquid flows ata limited rate when the valve is closed is controlled by a second valve,biased to closed position, and operating means are provided, manuallymovable to open the second valve and on further movement to open thefirst valve, which is also biased to closed position.

Two particular embodiments of the invention are further described below,by way of illustrative example, with reference to the accompanyingdrawings, in which:

FIG. 1 is an axial section through one form of liquid flow control meansand the drop pipe through which the liquid is delivered,

FIG. 2 is a similar axial section through an alternative form of controlmeans,

FIG. 3 is a diagrammatic view ofa modification of FIG. 2.

Referring first to FIG. 1, the valve illustrated comprises a main body1, to which is secured a flange 2, adapted for connection to a liquidsupply pipe. A resilient disc 3 makes a liquid-tight seal between theparts 1 and 2 and forms a seating for a valve plunger 4. The plunger 4is secured on a stem 5, which is slidably guided in the parts 1 and 2,the plunger assembly being urged into the closed position illustrated bya spring 6.

The plunger 4 is formed with passages 7 which (when the plunger is inthe closed position) permit liquid to flow at a limited rate from theinlet into the interior 8 of the body. The space 8 is in opencommunication with a drop pipe 9, com nected at one end to the body by aflange 10 and provided at its other end with a deflector spout 11.

The valve stem 5 is formed with passages 12, which connect the liquidflow passages 7 to a chamber 13 formed in the body and bounded on itsouter side by an annular diaphragm 14, the chamber being sealedfluidtight by an O-ring 15 surrounding the valve stem 5. The diaphragm14 is secured at its outer periphery between the body 1 and a cap 16,while its inner periphery is secured to the cap 1 by a tubular member17. A spring 18 acts on a locking sleeve 19 secured to the diaphragm 14to urge those parts into the positions illustrated. The locking sleeve19 has two parts of different diameters. When in the positionillustrated, the part of smaller diameter holds a number of loose balls20 engaged between a shoulder on the valve stem 5 and the stationaryabutment constituted by member 17, thus preventing the stem from movingagainst the action of spring 6. The chamber 13 is connected through apassageway 21 to an opening 22 provided in the delivery spout 11.

When liquid is delivered to the inlet, it flows at a restricted ratethrough the passages 7 in the valve plunger and is discharged throughthe drop pipe 9 and spout 11. The venturi effect of the flow of liquidthrough passages 7 causes a reduction in the pressure existing inpassages 12 and chamber 13, but so long as the passage 21 remains open,the pressure reduction in chamber 13 is insufficient to cause movementof the diaphragm 14. When the liquid level in the tanker or otherreceiving vessel has risen sufficiently to obstruct the open end 22 ofpassage 21, the pressure in chamber 13 is substantially reduced by thesuction applied through passages 12 and diaphragm 14 moves against theaction of spring 18, the movement of sleeve 19 permitting outwardmovement of the balls 20. The pressure of the incoming liquid on valveplunger 4 then overcomes the action of spring 6 and moves the valvemember off its seating 3, allowing liquid to flow to the drop pipe at anincreased rate. When the delivery of liquid ceases, spring 6automatically returns the valve plunger assembly to the closed positionshown, and the pressure in chamber 13 reverts to normal, so that spring18 returns the sleeve 19 to the locking position shown. The apparatus isthen ready for the next operation of the valve.

Referring now to FIG. 2, the modified valve illustrated comprises a mainbody 31, having a liquid inlet passage 32 and an outlet passage 33, thelatter communicating with a drop pipe 9 similar to that shown in FIG. 1.A port connecting passages 32 and 33 is normally closed by a valve disc34 carried by a valve plunger 35, slidably and sealingly guided in thebody 31 and urged downwardly by a spring 36. The upper end of the body31 is closed by a member 37, against which the spring 36 abuts, and acap 38, members 37 and 38 clamping between them a flexible diaphragm 39.The diaphragm is secured at its center to a shouldered tubular member40, which is slidably and sealingly engaged with a tubular extension 41of the cap A liquid passage 42 extends through the main valve plunger 35and is normally closed by a valve disc 43 carried on a stem 44 which isurged downwardly by a spring 45. The lower end of spring 36 and theupper end of spring 45 abut against a stem 46, which carries at itslower end a valve 47 normally closing a port connecting liquid passage42 to the upper side of main valve plunger 35. The stem 46 passesslidably and sealingly through the member 37 and its shaped upper endengages a number of loose balls 48, which are trapped between the parts40, 41 and 46. A downward extension of the stem of valve 43 carries aroller 49, adapted to be engaged by a cam arm 50, which is turnedclockwise to effect opening movement of the valve.

The liquid flow passage 42 controlled by valve 43 is so shaped as toproduce a venturi effect when liquid flows through it and create partialvacuum in a passage 51, formed in the main valve plunger. Passage 51communicates through a tube 52 with the chamber 53 on the lower side ofdiaphragm 39. Also communicating with this chamber is a tube 54 whichextends along the drop pipe through which liquid is delivered andterminates at a suitable point adjacent the end of that pipe, the endoftube 54 being open.

The drawing shows the parts in the closed position of the valve. Tostart liquid flow, arm 50 is manually turned clockwise, thereby liftingvalve 43 and allowing liquid to flow from inlet 32 to outlet 33 throughthe passage 42. Upward movement of stem 44 of valve 43 is arrested whena shoulder on this stem engages the lower end of the stem 46, upwardmovement of stem 46 being prevented by the blocking action of balls 48.The liquid flow through passage 42 applies suction to the passage Slland thus tends to reduce the pressure in chamber 53. However, so long asthe end of tube 54 remains open, the pressure in chamber 53 is notsubstantially reduced and diaphragm 39 continues to be held in theposition shown by the spring 55, so that member 40 carried by thediaphragm continues to hold the balls 48 in locking position. Turningmovement of operating cam 50 is thus limited to that required to effectfull opening of valve 43, which allows the delivery of liquid to thedrop pipe at the safe limited flow rate. When the level of the deliveredliquid has risen sufficiently to close the open end of tube 54, so thatit becomes safe to deliver liquid at a higher flow rate, the continuedapplication of suction to passage 51 reduces the pressure in chamber 53and the diaphragm 39 moves downwardly against the action of spring 55.The resultant downward movement of member 40 provides space for theoutward displacement of balls 48, so that stem 46 is no longer lockedagainst upward movement. Continued clockwise rotation of cam lever 50now causes the stem 44 of the first stage valve 43 to raise stem 46relative to the main valve plunger 35, thus opening valve 47 andequalizing the pressure on the two sides of the plunger 35. Stillfurther movement of lever 50 raises the plunger 35 and opens the mainvalve 34, permitting liquid to flow at a high delivery rate. The valvecan be kept fully open for as long as required, either by continuing themanual pressure on lever 50, or by means of a suitable stay-open device.When lever 50 is returned, or permitted to return, anticlockwise, allthe valve parts are returned to theirstarting positions by the springsand the balls 48 return to the locking position.

The tube 52 is shown as being of telescopic construction, but any otherarrangement which will afford a suction connection between passage 51and chamber 53 while allowing movement of the main valve plunger 35 canbe adopted.

Many other modifications are possible in each of the constructionsillustrated, these constructions being shown and described by way ofexample only. No attempt will be made to set out all the modificationspossible, but some of them are briefly noted below.

The passage whose closure allows the pressure in the diaphragm chamberto be reduced, thus permitting opening of the main valve can be providedwith a normally open branch, for example branch 54 shown in FlG. 2 whichis closed, (for example by means of a suitable solenoid device 57, onlywhen the receiving tank into which the drop pipe delivers has beenproperly earthed or grounded, thus ensuring that delivery at theincreased rate will not commence until that operation has beenperformed. When the tank has been properly grounded a signal istransmitted along 58 to the device 57 to cause the device to closebranch 56. lnstead of using suction to produce a subatmospheric pressurein the chamber on one side of the diaphragm, air under superatmosphericpressure may be supplied for example by a conduit 60, FIG. 3 from anysuitable source 59 to the chamber on the opposite side of the diaphragm39, the relief passage being also connected to that chamber so that thepressure in it does not rise appreciably until the liquid in thereceiving vessel has reached the required level.

l claim:

1. Means for controlling the flow of liquid through a drop pipe into avessel comprising a valve movable between a closed position in which theliquid can flow at a limited rate only and an open position in which theliquid can flow at a higher rate, a releasable locking device normallylocking the valve in its closed position, a pneumatic operating chamber,means responsive to the pressure in the operating chamber for releasingthe locking device to allow the valve to move to its open position, arelief passage communicating with the operating chamber and having anopening adjacent the delivery outlet of the drop pipe, therebymaintaining the pressure in the operating chamber substantially normaluntil the said opening is blocked by the rise of liquid level in thevessel, and means for applying a pressure differing from that of theatmosphere to the operating chamber, whereby upon said opening becomingblocked said nonatmospheric pressure is established in the operatingchamber and the locking device is released.

2. Means in accordance with claim 1 in which the passage through whichliquid flows at a limited rate when the valve is closed is so shaped asto produce a venturi effect and apply a pressure below that of theatmosphere to the control chamber.

3. Means in accordance with claim 1 in which the means responsive to thepressure in the operating chamber is a flexible diaphragm constituting awall of the chamber, release of the locking device being effected bymovement of the diaphragm.

4. Means in accordance with claim l in which the releasable lockingdevice comprises a rod which moves longitudinally upon opening andclosing movement of the valve and has a shoulder formed thereon, astationary abutment spaced axially away from the shoulder, a sleevecoaxially surrounding the rod and movable axially in response to achange of pressure in the control chamber, the sleeve having portions ofsmaller and larger diameter, and a plurality of free balls disposed inthe annular space between the rod and the sleeve, the smaller diameterportion of the sleeve normally holding the balls trapped between theshoulder on the rod and the stationary abutment to prevent axialmovement of the rod.

5. Means in accordance with claim l in which the passage through whichliquid flows at a limited rate when the valve is closed is controlled bya second valve, biased to closed posi tion, and operating means areprovided, manually movable to open the second valve and on furthermovement to open the first valve, which is also biased to closedposition.

6. Means in accordance with claim 5 in which the second valve is movablebeyond the position at which it is fully open to engage and open thefirst valve, the locking device preventing such further movement of thesecond valve until released.

7. Means in accordance with claim l in which the passage through whichthe liquid flows at a limited rate is permanently open and the valve isbiased to closed position but is adapted to move to open position (uponrelease of the locking device) in response to the pressure of the liquidthereon.

1. Means for controlling the flow of liquid through a drop pipe into avessel comprising a valve movable between a closed position in which theliquid can flow at a limited rate only and an open position in which theliquid can flow at a higher rate, a releasable locking device normallylocking the valve in its closed position, a pneumatic operating chamber,means responsive to the pressure in the operating chamber for releasingthe locking device to allow the valve to move to its open position, arelief passage communicating with the operating chamber and having anopening adjacent the delivery outlet of the drop pipe, therebymaintaining the pressure in the operating chamber substantially normaluntil the said opening is blocked by the rise of liquid level in thevessel, and means for applying a pressure differing from that of theatmosphere to the operating chamber, whereby upon said opening becomingblocked said nonatmospheric pressure is established in the operatingchamber and the locking device is released.
 2. Means in accordance withclaim 1 in which the passage through which liquid flows at a limitedrate when the valve is closed is so shaped as to produce a venturieffect and apply a pressure below that of the atmosphere to the controlchamber.
 3. Means in accordance with claim 1 in which the meansresponsive to the pressure in the operating chamber is a flexiblediaphragm constituting a wall of the chamber, release of the lockingdevice being effected by movement of the diaphragm.
 4. Means inaccordance with claim 1 in which the releasable locking device comprisesa rod which moves longitudinally upon opening and closing movement ofthe valve and has a shoulder formed thereon, a stationary abutmentspaced axially away from the shoulder, a sleeve coaxially surroundingthe rod and movable axially in response to a change of pressure in thecontrol chamber, the sleeve having portions of smaller and largerdiameter, and a plurality of free balls disposed in the annular spacebetween the rod and the sleeve, the smaller diameter portion of thesleeve normally holding the balls trapped between the shoulder on therod and the stationary abutment to prevent axial movement of the rod. 5.Means in accordance with claim 1 in which the passage through whichLiquid flows at a limited rate when the valve is closed is controlled bya second valve, biased to closed position, and operating means areprovided, manually movable to open the second valve and on furthermovement to open the first valve, which is also biased to closedposition.
 6. Means in accordance with claim 5 in which the second valveis movable beyond the position at which it is fully open to engage andopen the first valve, the locking device preventing such furthermovement of the second valve until released.
 7. Means in accordance withclaim 1 in which the passage through which the liquid flows at a limitedrate is permanently open and the valve is biased to closed position butis adapted to move to open position (upon release of the locking device)in response to the pressure of the liquid thereon.